edition: Use dyn syntax for trait objects

Found by running: `cargo rustc -- -D bare_trait_objects`

Bare trait objects like `&Trait` and `Box<Trait>` are soft-deprecated in
2018 edition and will start warning at some point.

As part of this, I replaced `Box<Trait + 'static>` with `Box<dyn Trait>`
because the 'static bound is implied for boxed trait objects.

TEST=cargo check --all-features
TEST=cargo check --target aarch64-unknown-linux-gnu
TEST=local kokoro

Change-Id: I41c4f13530bece8a34a8ed1c1afd7035b8f86f19
Reviewed-on: https://chromium-review.googlesource.com/1513059
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: David Tolnay <dtolnay@chromium.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/usb_util/src/usb_transfer.rs b/usb_util/src/usb_transfer.rs
index d3354ef..4dfe3e5 100644
--- a/usb_util/src/usb_transfer.rs
+++ b/usb_util/src/usb_transfer.rs
@@ -130,7 +130,7 @@ impl UsbTransferBuffer for BulkTransferBuffer {
     }
 }
 
-type UsbTransferCompletionCallback<T> = Fn(UsbTransfer<T>) + Send + 'static;
+type UsbTransferCompletionCallback<T> = dyn Fn(UsbTransfer<T>) + Send + 'static;
 
 // This wraps libusb_transfer pointer.
 struct LibUsbTransfer {